title: Antiproliferative activities of Garcinia bracteata extract and its active ingredient, isobractatin, against human tumor cell lines.
abstract: In our cell based screening of antitumor ingredients from plants, the EtOH extract of Garcinia bracteata displayed antiproliferative effect against human lung adenocarcinoma A549 cells, human breast cancer MCF-7 cells, and human prostate cancer PC3 cells. Phytochemical investigation of this active extract produced nine ingredients, and their structures were established by analysis of MS and NMR spectra. Antiproliferative evaluation of isolated ingredients on A549, MCF-7 and PC3 cells indicated that a xanthone named isobractatin (1) exhibited potent antiproliferative activity against the above three human cancer cell lines with IC50 values ranging from 2.90 to 4.15 μM. Treatment of PC3 cells with 1 led to an enhancement of the cell apoptosis, and arrested cell cycle in the G0/G1 phase. The G0/G1 phase cycle-related proteins analysis showed that the expressions of cyclins D1 and E were reduced by 1, whereas the protein level of cyclin dependent kinase (CDK) inhibitor P21 was induced. Additionally, 1 enhanced PC3 cell apoptosis by activations of Bax, caspases 3 and 9, and by inhibition of Bcl-2. Our combined data illustrated that isobractatin (1) was the antiproliferative ingredient of G. bracteata against three human cancer cell lines, which exerted its antiproliferatrive effect via cell cycle arrest and induction of apoptosis.
authors.affiliation: Key Lab of Chemical Biology (MOE), School of Pharmaceutical Sciences, Shandong University, Jinan, People's Republic of China.
authors.forename: Tao
authors.initials: T
authors.lastname: Shen
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.forename: Yan-Yan
authors.initials: YY
authors.lastname: Wang
authors.forename: Qing-Qing
authors.initials: QQ
authors.lastname: Zhong
authors.forename: Shu-Qi
authors.initials: SQ
authors.lastname: Wang
authors.forename: Xiao-Ning
authors.initials: XN
authors.lastname: Wang
authors.forename: Dong-Mei
authors.initials: DM
authors.lastname: Ren
authors.forename: Hong-Xiang
authors.initials: HX
authors.lastname: Lou
mesh_terms: D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects* / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D029760:Garcinia; D006801:Humans; D061986:MCF-7 Cells; D035261:Plant Components, Aerial; D010936:Plant Extracts / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*
chemical_list: D010936:Plant Extracts